A pathology report (sometimes called a surgical pathology report) is a medical report that describes the characteristics of a tissue specimen that is taken from a patient. The pathology report is written by a pathologist, a doctor who has special training in identifying diseases by studying cells and tissues under a microscope.
A pathology report includes identifying information (such as the patient’s name, birthdate, and biopsy date) and details about where in the body the specimen is from and how it was obtained. It typically includes a gross description (a visual description of the specimen as seen by the naked eye), a microscopic description, and a final diagnosis. It may also include a section for comments by the pathologist.
The pathology report provides the definitive cancer diagnosis. It is also used for staging (describing the extent of cancer within the body, especially whether it has spread) and to help plan treatment.
Common terms that may appear on a cancer pathology report include:
The pathologist examines cells or tissues obtained during a biopsy (which is a procedure to remove a cell or tissue specimen for examination by a pathologist) or surgery or from bodily fluids.
A biopsy specimen can be obtained in several ways, such as by
If surgery is used to remove part or all of a tumor, some or all of the removed tumor specimen will be examined by the pathologist. If the entire tumor is removed, typically the surgeon will attempt to remove some normal tissue around the tumor (known as the margin) for examination by the pathologist to make sure that it doesn’t contain tumor cells.
For some cancer types, especially breast cancer and melanoma, the surgeon may also remove nearby lymph nodes, called the sentinel lymph nodes, so the pathologist can see if these contain cancer cells. The Sentinel Lymph Node Biopsy fact sheet describes this procedure and its use in determining the extent, or stage, of cancer in the body.
A pathologist may also examine cells that are present in bodily fluids, such as urine, cerebrospinal fluid (the fluid around the brain and spinal cord), sputum (mucus from the lungs), peritoneal (abdominal cavity) fluid, pleural (chest cavity) fluid, cervical/vaginal smears, and bone marrow.
Tissue or cell specimens must be cut into very thin slices, called sections, so the pathologist can look at them under a microscope. The specimen must be processed to make it solid before it can be cut into sections.
The most common approach used for tissue examination involves chemically “fixing” the specimen, usually with a chemical called formalin. This stabilizes the cells for further processing in an automated machine that submerges the tissue in substances that remove water and replace it with molten paraffin wax.
Once processed, the tissue is embedded into a permanent paraffin wax block to be cut. The paraffin-embedded tissue is then sliced into very thin sections that are placed onto microscopic slides. The slides are stained with dyes to help visualize parts of the cell and structures in the tissue. This is known as histologic (tissue) examination.
Fixed sections provide the maximum detail of the structures in a tissue sample, and they can be saved and analyzed in the future if needed. Preparing fixed sections normally takes several days. The pathologist typically sends a pathology report to the doctor within 10 days after the biopsy or surgery is performed.
Frozen sectioning is another approach used by a pathologist for tissue examination. Frozen sections are prepared when an immediate answer about a tissue sample is needed. For example, this type of examination would be used during surgery to provide the surgeon with a rapid diagnosis for an area of abnormal tissue and the extent of the abnormal area while the patient is in the operating room. To make frozen sections, the tissue sample is rapidly frozen, cut into sections using an instrument called a cryostat, stained, and examined by a pathologist. This can be done in about 15 to 20 minutes.
Frozen sections are suitable for preparing tissue for some tests, such as immunofluorescence and immunohistochemistry. However, the fixed (permanent) section preserves more detail and is more commonly used to make a diagnosis than frozen sections.
The gross description includes the color, weight, and size of a tissue sample as seen by the naked eye. It may also include the shape of the tissue sample and any visible abnormalities. And it will indicate the body site from where the tissue was taken from, how many samples were taken, and whether and how many lymph nodes were removed.
The microscopic description in a pathology report includes information about the appearance of the cells after they have been stained with routine stains such as hematoxylin and eosin (also known as H&E) and viewed under the microscope. H&E staining helps identify different types of cells and tissues and provides important information about the pattern and shape of cells and the structure of the tissue. With H&E staining, hematoxylin shows the ribosomes, chromatin (genetic material) within the nucleus, and some other structures in the nucleus as a deep blue-purple color. Eosin shows the cytoplasm, collagen, connective tissue, and other structures that surround and support the cell as an orange-pink-red color.
This description may also include the type and number of cells seen in the tissue sample, how abnormal the cells look (also called the tumor grade), and whether there are notable cell features (such as their arrangement and behavior).
The microscopic description section will also indicate whether abnormal cells are found in the margins (the edges of the tissue that has been removed by surgery) or in lymph nodes. Margins are described as negative (or “clean”) when the pathologist finds no cancer cells at the edge of the tissue, suggesting that all of the cancer has been removed. A margin is described as positive (or “involved”) when the pathologist finds cancer cells at the edge of the tissue, suggesting that some of the cancer has not been removed. Lymph nodes are called positive if they have cancer cells and negative if they do not.
This description may also include the results of additional tests that were performed on the tissue. Depending on the cancer type, these may include tests that
Source: National Cancer Institute